KR100211962B1 - Mono input/output sequence generating method - Google Patents

Abstract

The present invention is a method for generating a single input / output (UIO) sequence of shortest length for any state to be tested, and the conventional method provides systematic information on how to reach the state to be tested in step 1. In addition, there are various methods of generating the UIO sequence used to determine the output for a given input in Step 2, and because the length of the generated UIO sequence is long, the test period and the test cost are large. The invention generates a UIO sequence using Petri nets with excellent parallelism and asynchronous properties, reducing test periods and costs for products, and applying test results to implementations to improve product quality.

Description

How to create a single input / output sequence

The present invention relates to a method for generating a conformance test sequence using a Petri net having a complex, parallel and asynchronous property, and the error in the design and implementation of the protocol as the size and complexity of the information communication protocol increases. Is more likely to occur.

Conformance testing refers to the use of a test suite to evaluate whether an IUT (Implementation Under Test) conforms to a specification, and a test suite is an input / output pair extracted from protocol specifications. ) Or a sequence of input symbols to test transitions.

Protocol specifications or international standards described in natural language may be implemented differently depending on the interpretation of the implementer due to ambiguity, inconsistency, and instability of the described specification itself.

Therefore, in case of testing with the test sequence generated from the specification written in natural language, the test result varies according to the test performer and also includes errors in the test process.

In order to overcome the shortcomings of the natural language, the test period and cost are reduced through the generation and automation of test suites from the specification described by the formal description technique (FDT) and the specification described by the formal description technique.

However, formal description techniques (FDT), such as Estelle, LOTOS, and S, provide sufficient functionality to describe the protocol, but lack the consideration of conformance testing aspects, and therefore cannot be directly compared with the contents of the specification for testing the IUT.

Therefore, in the method of generating a suite for a conventional protocol test, a research is being conducted to generate a test sequence by converting the FDT into a finite state machine (FSM).

In order to achieve the above object, the present invention proposes a method for shortening the length of the test sequence used for protocol conformance testing and reaching the shortest path to the state to be tested to reduce the test period and the test cost.

1 is a protocol test procedure diagram applied to the present invention.

2 is an illustration of an output error according to the present invention.

Figure 3 is an illustration of a transition error in accordance with the present invention.

4 is a Petri net configuration diagram for generating a single input / output (UIO) sequence of the present invention.

5 (a) to 5 (d) are diagrams of a firing tree for length 1 of the present invention.

6 (a) to 6 (d) are diagrams of a firing tree for length 2 of the present invention.

7 (a) to 7 (d) are diagrams of a firing tree for generating a single input / output (UIO) sequence according to the present invention.

* Explanation of symbols for main parts of the drawings

1: specification 2: test series generation

3: Test Sequence 4,5,9,10,15,16,24, ..., 30,43, ..., 50: Input / Output

6: implementation 7,8,11,12,13,14,17, ..., 22,31, ..., 42: place

The present invention is a method for generating the shortest length of a unique input / output (UIO) sequence for any state to be tested, and in particular for testing errors in implementations in the field of protocol testing. It exists only in the desired state and relates to the generation of a single input / output sequence of the shortest length among the existing single input / output (UIO) sequences.

The present invention exists solely in the state to be tested used to check for errors in implementations in the field of protocol testing, and is a detailed description of the generation of a single input / output sequence of the shortest length among the single input / output sequences present.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a protocol test procedure diagram applied to the present invention.

Looking at the above process, the implementation 6 is placed in the state to be tested corresponding to the specification 1 in the initial state 19.

The output 5 generated by applying the test sequence input 4 obtained in the specification 1 to the implementation is determined.

Check that the output 5 produced in the implementation is equal to the output 1 described in specification 1 and check that the state of arrival is the same as that of the specification.

After performing the procedure, the implementation is placed in an initial state 19 for the next test.

The protocol test field exists only in the state to be tested used to check for errors in the implementation 6, and generates the shortest length single input / output sequence among the single input / output (UIO) sequences present. 2) is the description.

In the protocol testing process, the following two problems generally occur in the conformance test step of step 1 to step 3 to filter out output errors and transition errors.

In the above step 1, the implementation petrinet cannot be placed in the desired state, and secondly, even if the desired output is obtained from the implementation petrinet after applying the input of the test series in the step 3, the implementation petrinet can be placed in the state. It is not known if it is located.

In addition, it is not possible to confirm whether the transition to the initial site is possible for the next test in step 4.

The first problem is controllability and the second problem is observability, and the last problem is resilience.

In general, the first input of the place arrived after the transition to test the problem after the arrival at the place using the shortest pass from the initial place P ₀ to the desired place to solve the control problem, and to solve the observation problem. The output sequence is included in the test sequence and then applied to determine the transition set of the implementation Petri net.

A unique input / output (UIO) sequence, a distinguish sequence (DS), a character set (DS) sequence, or the like is used as the unique input / output sequence.

The single input / output sequence exists for most of the places and is shorter than the distinguishing sequence (DS) or the feature sequence (CS), so as a result, short test sequences are generated, which is often used to solve observation problems. do.

2 is an exemplary view of an output error according to the present invention.

This example illustrates a case where an unexpected output 10 for a given input 9 appears as an output error requiring confirmation during protocol testing.

A method of generating the shortest length single input / output (UIO) sequence used to solve the observation problem in black box testing as shown in FIG. 1 is proposed as follows.

Here, the single input / output (UIO) sequence is denoted as UIO (Pi) for place Pi of a given Petri net, that is, a set of forward arcs or a sequence of predicates / actions at place Pi.

In this case, the prediction corresponds to an existing input and an action corresponds to an output.

3 is a diagram illustrating a transition error according to the present invention.

The above example shows a case where a transition to an unexpected place 18 occurs for an input 15 given as a transition error that requires confirmation during a protocol test.

In addition, the above example uses a method for generating a single input / output sequence in consideration of the characteristics of the Petri net, which is a model used in the present invention.

First, we create a tree with the transition at each place for length 1 as the edge and the leaf as the next place.

If a place with a unique transition in the generated tree exists, it is recognized as a single input / output (UIO) at that place.

If there is no single input / output (UIO) and a location of length 1 in the recognition process, the process of the tree generation process is repeated with length 2 for the transition except for the transition selected as the single input / output.

In the obtained tree, edges having the same set of arrival trees or having the same firing sequence are removed.

If there is an edge in all the places, the following process is performed, and if there is no edge in any place, the next last process is performed.

Consider the edge sequence at each location as a single input / output (UIO) at that location and reach the initial state with the shortest length if there are multiple single inputs / outputs (UIO) at any location. A single input / output (UIO) is chosen as the single input / output (UIO) at that location.

Returning to the removed edge again, the third, fourth and fifth processes are repeated.

4 is a Petri net configuration for generating a single input / output (UIO) sequence of the present invention.

The definition of the Petri net model used to prove the validity and efficiency of the present invention is as follows.

P is a set of finite places and has {P1, P2, ..., PN}.

In addition, T is a set of finite transitions and has {T1, T2, ..., TN}.

A is a set of finite arcs and has a set of forward arcs of {P × T} ∪ {T × P} and a set of reverse arcs of {T × P}.

Next, M0 is an initial state set of P → {0,1, ...} tokens and has a set of P∩T = 0 and P∪T ≠ 0.

This structural representation of Petri nets consists of places, transitions and arcs based on the directional graph representation.

As above, each place P [19,20,21,22] is represented by a circle and the transition T [23, ..., 30] is represented by a bar.

Here, the function of T is a position of a finite input / output indicating a condition of occurrence of an event and a condition after occurrence.

Arc A connects P and T to determine the input and output locations of T.

There may be one or more tokens in each place of the Petri net, each of which is represented by one black dot 19.

It expresses the current operating state of the system according to the state of the token at any place, which is called before enabling a transition if the token exists at the input site of a transition.

These tokens are called enabling tokens.

On the other hand, there are a variety of petri nets, such as the colored net from the Black White net to the simple and simple to analyze, the present invention used a free kit / action net.

The FriedKit / Action Net is labeled for each transition.

The label consists of a free kit and an action. In order for a transition to ignite, the Freddie kit in the ignitable state must be true, and the action is performed with the ignition.

The Freddie kit is a simple proposition or marked with? M to determine whether it received M.

The action also sends a message M, denoted by! M.

5 (a) to 5 (d) are diagrams illustrating a firing tree for length 1 of the present invention.

The schematic shows the state of reaching the next using the token for each location 19, 20, 21, 22 as the ignition tree for FIG. 5.

First, a firing tree for length 1 is created, and the firing tree for each place [31, 36, 41, 46] is shown.

Transition T4 33 is uniquely present only for place P1 31.

A Firing Tree having a length of 2 except for the transition T4 33 at the place P1 33 is generated.

At this time, the firing tree for each place is shown in FIG.

6 (d) to 6 (d) is a configuration diagram Firing Tree for the length 2 of the present invention.

This configuration removes the edges 56, 65, 62, 74, 81, 92 having the same ignition tree to create a firing tree as shown in the next seventh degree.

The dashed arrows here indicate the removed edges 104, 110, 113, 122, 129, 140.

7 (d) to 7 (d) is a configuration diagram of a firing tree for generating a single input / output (UIO) sequence applied to the present invention.

The single input / output (UIO) sequence for each location (19, 20, 21, 22) of the firing tree configuration is P1 (T4, T3 T3), P2 (T1 T4), P3 (T3 T1), P4 (T1, T2 T2, T2 T1) is selected from.

In the case of P1, T4 23 is selected as a single input / output (UIO) sequence in P1 19 in consideration of the length of a single input / output (UIO) sequence.

In the case of P4 (22), there are three cases. As shown in FIG. 5, the lengths of the paths to reset and return to the initial place are the same, so that all three single input / output (UIO) are the same. Has a result.

Therefore, the results obtained using the single input / output (UIO) sequence generation algorithm are as follows.

P1: T4, P2: T1, T4, P3: T3 T1, P4: T1 T2, T2 T2, T2 T1

The present invention provides a protocol tester with a systematic conformity test method to reduce the test period and the test cost for the product and to improve the quality of the product by applying the test results to the implementation.

The protocol test must be performed to protect the user and to improve interoperability in an open market environment or in areas that require a lot of time and money.

Therefore, research is needed to shorten development costs and periods and to improve quality.

The present invention is expected to contribute to securing technology in the open protocol field by providing such a research environment.

The present invention relates to a conformance test that confirms whether a product implemented with a protocol standard recommended or standardized by an international standard organization (ITU, ISO, etc.) matches, and is more parallel and asynchronous than a conventional finite state machine (FSM). Using a method of generating test sequences from Petri nets with excellent properties, the length of the test sequence and the cost are reduced because the length of the test series is shorter than that of the existing test series.

Claims (4)

In the UIO sequencing method in consideration of the characteristics of the Petri net, a tree in which a transition at each place with respect to the length (l) of a sequence of 1 is used as an edge and a next place is a leaf is generated. A first step; A second step of recognizing a place having a unique transition in the generated tree as a single input / output (UIO) at that place; If the single input / output (UIO) and the location of the sequence length (ℓ) in the recognition process does not exist, the length of the sequence (ℓ + 1) for the transition except for the transition selected as the single input / output (UIO) A third step of repeating the process of generating the tree; Removing an edge having the same set of arrival trees or having the same firing sequence in the obtained tree; A fifth step of performing the following process when the edges exist in all the places, and performing the next last process when the edges do not exist in any place; Consider the edge sequence at each location as a single input / output (UIO) at that location and reach the initial state with the shortest length when there are multiple single inputs / outputs (UIO) at any location. A sixth step of selecting a single input / output (UIO) as the single input / output (UIO) at the place; And returning the removed edge again to repeat the third, fourth, and fifth steps. 2. The single input / output of claim 1, wherein the third step removes edges having the same arrival path or ignition sequence to find a unique single input / output (UIO) sequence in a state. How to create a sequence. 4. The single input / output of claim 1, wherein the fourth step removes edges having the same arrival path or ignition sequence to find a unique single input / output (UIO) sequence in a state. (UIO) Sequence generation method. The method as claimed in claim 1, wherein the sixth step selects a sequence having a short path returning to an initial state from among a plurality of single input / output (UIO) sequences present in a state as a representative single input / output (UIO). Single input / output sequence generation method.